Intronics 75A MPPT Controller

As I was crusing through Ebay this morning, looking for a steal of a deal on a Classic or FM60 (as anticipated, there weren't any), I came across a brand of CC that I hadn't seen before. It's listed as being made by a company called Intronics out of Norwood, MA.

From looking at the spec sheet, I don't think that it's anywhere near as good as the more popular controllers out there, but I thought I'd share anyway to see what the the experts think.

Comments

As I was crusing through Ebay this morning, looking for a steal of a deal on a Classic or FM60 (as anticipated, there weren't any), I came across a brand of CC that I hadn't seen before. It's listed as being made by a company called Intronics out of Norwood, MA.

From looking at the spec sheet, I don't think that it's anywhere near as good as the more popular controllers out there, but I thought I'd share anyway to see what the the experts think.

The basic features seem to be there, with adjustable voltage set points and a reasonable choice of two modes for the Aux output. But the maximum Voc limit of 65 volts does not give you much room to run two or more panels in series for a 24 volt system and still work with one or more panels partially shaded. You could not, for example, use two 30 volt Voc panels in series after allowing for cold weather.

The price would have to be really good and your system and panel voltages would have to be within a limited range.

Actually it says the maximum input Voltage is 80 (still not very much) and the maximum battery Voltage is 65. This doesn't make sense either, as it is for either 12 or 24 Volt systems so where would you get 65 Volts on the battery?

Actually it says the maximum input Voltage is 80 (still not very much) and the maximum battery Voltage is 65. This doesn't make sense either, as it is for either 12 or 24 Volt systems so where would you get 65 Volts on the battery?

Very confusing. Possibly you could set the "nominal" battery voltage to 24 and then adjust the setpoints through the menu to be suitable for a 48 or 60 volt battery bank instead?
Also the specs say max input voltage= 80, but the text on panel selection farther down states:

The controller will work with panels with
maximum open circuit voltages up to 65 volts.

Good question. One of the most troubling aspects of specs on these "low end" controllers is the way they contradict and confuse while trying to explain.
You'd think if it could be set for 65 Volts out they'd include "48 Volt" as a system option. As for the Voc limits .... What panel has a Voc of 65? 44 maybe, which times two would be 88 and therefor over the 80 Volt input max. Even using cold temp factors these numbers just don't line up for any "standard" panels I can think of.

It just sort of leave you wondering what the numbers really are, which is no help in trying to decide on whether or not to buy it.

Good catch. Their battery wire recommendation is "...#10 gauge or 4mm wire or heavier...."
The connectors should be able to take at least #8, which is marginal for 75 amps if the wires are short.
For "chassis wiring" it should really be #8 or larger, while for NEC it should be #6 or larger, depending on the insulation type. Conservative would be #4 or even #2.

Good catch. Their battery wire recommendation is "...#10 gauge or 4mm wire or heavier...."
The connectors should be able to take at least #8, which is marginal for 75 amps if the wires are short.
For "chassis wiring" it should really be #8 or larger, while for NEC it should be #6 or larger, depending on the insulation type. Conservative would be #4 or even #2.

I doubt that #2 would fit those terminals, but .....

hey im new to the forum and the solar off grid scene,
ive got the mppt 75 its a good cc for the price. we have 1.9 kw array in parelell 8 toppoint 245w 59.4 voc panels that work well with this controller

we have a 24v batterry bank 3 strings of 4 cheap 6v golf cart deccos, a power bright 3500w inverter( we keep that draw under 2000w and are input is 1960w maxfor a 24v system)

the mppt 75 will hold a #4 guage wire which i have a short run that junctions a 2/0 aluminium 20' run to the roof (salvaged 200amp house service cable)

Sounds like exactly the set up I was going to use. 6. 320 watt x24 volt panel. How does the battery bank support a frigid and lights constant use. I'm up nort off the grid. I've been wondering about setting up 10 x320 watt panels to allow for lower production in the winter

Yes, start a new thread with your questions as Littleharbor2 suggests--That will work out best.

Also, we will need to know more about your system. Those "24 volt panels" are probably Vmp~30 volt panels. If you are using a 24 volt battery bank, you will need to set the array up with 2 panels in series (Vmp-array~60 volts) to properly charge a 24 volt battery bank with an MPPT type charge controller. You cannot use (efficiently) a PWM charge controller with Vmp~30 volt panels.

I own the controller you guys are falsly claiming to be crap! It has been up and running flawlessly in my RV for over 18 months with 3-315 watt pannels that operate @ about 40volts I have the controller set to 12vdc to charge my 4- Trojans (150ah)and I also have 4- Deka Ungy batts (94ah each)total mis match and works great and gives me a total 976 ah's, despite what all of the "solar experts" would like to tell everyone... The controller is managable the only issue with running a bank of lead acid batts with a bank of AGM batts is that I can't equalize without disabling the AGM bank, not a problem though! I'm in Albuquerque and the camper is parked in full sun, so I get at least 5 hrs per day, I'm running a cheap 2000 watt Harbor freight inverter with a small dorm fridge 24/7 (nothing in it, just keeping a load on the batteries) Bottom line this controller does it all and is MADE IN THE USA!

Those "24 volt panels" are probably Vmp~30 volt panels. If you are using a 24 volt battery bank, you will need to set the array up with 2 panels in series (Vmp-array~60 volts) to properly charge a 24 volt battery bank with an MPPT type charge controller. You cannot use (efficiently) a PWM charge controller with Vmp~30 volt panels.

-Bill

With the Intronics controller you would just run you panels in series to maintain your 30-40 volt output, the issue you will have with the MPPT75 is that it is limited to JUST 78 amps, so at 12 volts the current will be automatically capped at 936 watts or 3-310 watt panels (9-100watt), this is why you would want to run 24vdc/36vdc or 48 vdc(the MPPT75 will run at all of those voltages).

@ 24v 78 amps allows you to have 6-310watt panels! 36vdc allows you to use 2808 watts of solar; and 48 volts allows a max of 3774 watts for a total of 12- 310watt panels on just one mppt75 controller! So, the MPPT75 controller is an extremly versitle choice, and it's priced right!When I ordered mine I called the company and actually talked to the owner, they make these in housewith quality components, the only thing It is lacking is a remote lcd panel or pc connections, other than that, it is quality all the way

My setup is running @ 12volts on my camper with 3-315 watt panels the current is cut to 936 watts, instead of 945 watts, so Ioose 9 watts by running at 12vdc, I'm ok with that since it is not worth the price of a 24v inverter and my aux. 12v power would also be converted to 24vdc and no longer work with my lights or water pump....

I was just reading through some of the other posts in this thread, and man are you folks misinformed! My MPPT75 accepts 2 ga wire just fine, in fact I dont recomend anything less than 4ga wire! I found a great deal on 4ga wire at HomeDepot the Husky 20' 4ga.jumper cables cost only $20 and you get two 20' 4ga. wires and they are color coded to boot! If you have issues getting 2ga wire into the controllers connectors, just trim some of the wire off and tighten em' down!

I just realized that the above post was from a "grid tied expert" Grid tied systems don't even use charge controllers, except for backup purposes! When I had a grid tied home, I just used inline inverters, no batteries, no controller, in fact I didn't have to do anything to maintain the system! It was so nice! Now I check up on the condition of things at least twice a week, check water, voltage, temps, etc...

.... The controller is managable the only issue with running a bank of lead acid batts with a bank of AGM batts is that I can't equalize without disabling the AGM bank, not a problem though! I'm in Albuquerque and the camper is parked in full sun,.....

Be very careful, many AGM batteries do NOT want to be EQ'd, and those that do, have very specific instructions you should follow.And if you are running AGM & Flooded in parallel, that's a problem, and I'm glad it's yours, and not mine.